When the air pressure upon the surface of the water is lessened, the water boils at a lower temperature. As the altitude increases, the air pressure decreases, as many a mountain traveler knows to his cost. The boiling temperature of water is so much lowered that the dwellers in high regions of several thousand feet find it difficult to cook starchy vegetables well. A heavy iron pot is made with clamps for fastening down a tight cover, which increases the temperature somewhat. Experiments D and E indicate a method that can be used to a small extent. The baking process should be largely used, and boiling avoided. For meat, eggs, and fish the lower temperature is not undesirable. (See the chapters relating to these foods.)